Thomas Ashby, 1911 Encyclopædia Britannica (1911)
“ The most magnificent part of the exterior and indeed the finest polychrome monument in existence is the west façade, built of richly sculptured marble from the designs of Lorenzo Maitani of Siena, and divided into three gables with intervening pinnacles, closely resembling the front of Siena cathedral, of which it is a reproduction, with some improvements. With the splendour of the whole, the beauty of the composition is marvellous, and it may rank as the highest achievement of Italian Gothic. It was begun in 1310, but the upper part was not completed till the 16th century. ”
